What is the meaning of Zzz?

A snoring sound, implying that somebody is asleep.

To sleep or snore.

zzz (sleeping)

indicates that one doesn't care about or agree with what is being said

buzz (sound made by some insects' flight)

zzz (sleeping)

Indicates that one doesn't care about or agree with what is being said because is boring.

Source: wiktionary.org